DK171620B1 - Method and system for handling samples of particulate materials in installations, where such samples are regularly taken from a number of sources for supply to an internal central analysis unit - Google Patents

Abstract

Samples taken automatically and frequently from the outlets of silos (4) in mixing plants, e.g. for fodder mixtures, are brought unwrapped and successively to an automatic NIR analysing station (72, 26) through a pneumatic conveyor system with substantial common pipe stretches (36) between that station and the single samplers (34). The associated risk of contamination of the samples is counteracted by taking out and conveying sample portions which are much larger than what is required for the analysis itself, and the large sample portions are not wasted, as they are returned to their silos of origin through another pneumatic conveyor system (90). It is hereby possible to operate with a real on-line analysing and thus, with computer support, to effect required changes in the mixing recipes almost immediately in response to changed analysis results. Various specialized sample handling equipment for making the system operative is disclosed.

Description

DK 171620 B1

The present invention relates to a method for handling materials in silos, mixing stations, process plants or generally in plants for receiving, trading or delivering materials, where material samples are regularly taken for control analysis in an analysis center, in particular in connection with with the handling of materials intended for animal or human food. The application also relates to a plant for carrying out this method.

In the manufacture of feed or food in industrial plants with e.g. a larger silo battery for different material components, it is crucial that samples are taken continuously or at least as often as possible of the components dosed from the silos, so that corrections in dosage can be taken as early as possible. or choice of material if significant changes occur in the component content of characteristic substances, e.g. in the fat or protein content of one or more of the raw materials. Quite elementally, this can be done by taking a sample of material carried by the flow from a selected silo, which is carried 20 to a sample laboratory, from which a result of the analysis can be reported after a shorter or longer period, according to which the analysis can be performed. decision on any desired worthy corrections. However, automatic analysis kits have been developed, which on 25 basis of a very small sample can complete a relevant analysis in just a few seconds, and it can therefore be an opposite extreme that at each of the silo outlets, such equipment is placed as near as possible. can provide continuous analysis of the material in question. However, it will be clear that such an arrangement is unrealistically expensive.

Also, in various other handling and processing plants, it may be important to obtain rapid analysis results from several sampling sites, e.g. for quality-based settlement for received materials or for checking or declaring goods delivered.

It will be an attractive solution that the fast-working analytical equipment is placed in the analysis center and samples are quickly fed in succession from the different sampling points, but in large plants this requires a very complicated transport procedure and is therefore not used in practice. A proposal is known that the samples can be filled into pipe mail cartridges, which can then be sent to the analysis center 5 in a pipe mail plant, but for several reasons this must be considered unrealistic; Although the transport itself can be reasonably rational, there will be major problems with the material handling during the filling and emptying of the cartridges and there will be pollution problems for the 10 samples themselves when they are delivered to the analysis centers where the samples can be contaminated by residues from previous samples. . Similar pollution problems will arise in plants where it is necessary to comminute at least some of the incoming material components prior to analysis; an efficient comminution requires a relatively expensive equipment, and if separate comminution units are to be avoided at the individual sampling points, the samples must be delivered to a central comminution apparatus connected to the analysis center, whereby, based on the prior art, it will be virtually impossible to avoid significant contamination of the consecutive samples.

The object of the present invention is to provide a method and associated handling system, which will enable realistic and advantageous work of local sampling in connection with just a single or at most a few analysis units.

The invention is based on the fact that it is relatively simple to transport the material samples all the way to the analyzing unit, when this can be done by pneumatic transport through a transport tube with the sample in free and unpacked condition, as this will also be possible - just as in the above-mentioned piping system - to use certain common sections of the transport system for the final transport of the samples to a single point of delivery. However, when it is possible - and desirable - to use very small sample portions, this mode of transport for samples will be disqualified in advance because the said sample contamination will be highly pronounced. In accordance with the invention, however, this disadvantage is counteracted by the use of relatively large sample portions, e.g. several hundred times greater than the amount required for the assay itself, whereby any remnants of pre-carried sample portions contained in said common conveyor lines will or may be mixed into the new sample portion with such admixture as is sufficiently low to be fully acceptable taking into account the requirements of analytical accuracy. Thus, no unrealistic attempt is made to clean the transport lines, and in practice the large portion size required will be reasonably moderate, e.g. of the order of 1-6 liters, preferably 3-5 liters.

It is a closely related problem that how a representative sample of a few grams can be produced from these relatively large sample portions. The fast-acting analyzers in question work on the basis of the so-called Near Infrared Reflection (NIR) principle, where a material sample with a thickness of 35 few millimeters is exposed to a low frequency light 20. An isolation of a very small sample could be achieved by repeated subdivisions of or from the large sample portion, but this is complicated and problems can easily arise with respect to the sample. the correct representation of the subdivided sample. In the invention, cf. Claim 2, it is realized that there is no need to think about small sample portions, since the entire large portion can be collected in a container which, at a small surface area, can allow operational access to perform the said surface irradiation of the sample material. . It is sufficient that the irradiated material layer has a thickness of a few millimeters and it will be unaffected by the analysis whether the overall layer thickness is far greater, and for this reason the entire large sample portion can only be collected in a simple, large container in which any surface area of the material may be representative of the sample as a whole. Since in the pneumatic conveying system considerable turbulence will occur, the residuals from the previous sample transfers will not tend to occur precisely in the surface layer of the total material in the container; rather, the residuals in question will be evenly distributed in the new sample material, and the analysis result can therefore be fully reliable within the tolerances used.

The said relatively large sample portions of e.g. However, 3-5 liters or even 2-10 liters will be small portions when the sample material is taken from an outlet of tons of material; however, the dosages of materials are often far smaller, and in addition, frequent sampling is aimed at, so that the relatively large sample portions in both cases will represent considerable quantities of the materials in question. It is therefore advantageous and feasible, both operationally and systematically, to ensure that the samples are returned as far as possible to the respective 15 sampling areas, so that they do not go to waste, cf. that of claim 3.

It will be essential that the individual sample portions in the central assay station can be handled and thus also removed quickly, but it should be borne in mind that an associated computer processing of the assay result may take some time, albeit not a long time, and it may be quite important to be able to withhold a test until it is determined whether the analysis result corresponds to an expected result or if it could be of particular interest for a further analysis, e.g. for a recalibration or reliability check of the entire analysis system. If the test gives rise to a divergent but expected result due to reasonably natural changes in the material properties, it may be appropriate to allow a computer system to produce a correction in the dosing of the material, or in the material selection or a corresponding settlement, but atypical changes may occur. is due to a change in the calibration of the analyzer, so it may be desirable to subject the sample concerned to an accurate chemical analysis 35 to provide additional information to the computer.

In such cases, the entire material portion could be isolated by selective discharge from the NIR sample container, but the relatively large sample portion would be unnecessarily large for performing a laboratory analysis, and otherwise, as mentioned, it may be desirable that the large portion or most of it can be immediately returned to its city of origin.

In the embodiment specified in claim 4, it can be achieved that a sub-sample of a suitable small volume can be taken from the sample portion in the atypical situation concerned, so that the sample container can be prepared for receiving the next sample portion.

It is essential for the invention that the material in the samples to be introduced from the sampling points into the pneumatic conveying system must be sufficiently comminuted to be transportable without forming accumulations in the conveying system, and it is a further condition that the material must be even more comminuted upon its introduction into the sample container of the NIR analysis center, as proper analysis is contingent upon a very extensive comminution of the material.

The comminution required for the transport itself can be performed locally by "coarse comminution" aggregates located at all inputs to the transport system, while a further comminution for analysis can conveniently be performed in a central fining apparatus located immediately before the analyzer.

Certain sample portions may consist of a powder material which will not require further comminution prior to introduction into the assay container or test chamber, but the preliminary "coarse-grained" samples may be selectively passed through the "fin finder" prior to this introduction. An advantage of this is that only a single, expensive fine-cutter device is necessary, but it is a related overall problem that the fine-cutter must be able to process the material in such a way that in this unit no significant residues of the treated portions of material are left, as this would involve significant contamination of the following samples. Already for this reason, conventional grinders such as slag mills will be useless, and instead an efficient fine-cutting apparatus is provided by the invention which can comminute the material extensively by means of a rotary knife system so that 1) the disintegration of the material will be sufficiently fine. DK 171620 B1 6 for performing a 30 NIR analysis, 2) so that no residue of the successive sample portions will be left in the apparatus, and 3) the flow rate of the successive samples will be controllable as needed to subject 5 the samples individual degrees of machining to achieve the desired degree of fineness as quickly as possible.

The invention will now be explained in more detail with reference to the drawing, in which: FIG. 1 is a schematic overview plan of a plant according to the invention; FIG. 2 is a perspective sectional view of a sample terminal; FIG. 3-5 different views of a sample container; 6 is a side sectional view of a sample distributor; FIG. 7 is a sectional top view of the same, and FIG. 8 is a perspective view of an associated NIR analysis unit.

In the embodiment of FIG. 1, a silo battery 2 with single silos 4 is placed above a container weight 6 and has dispensing means 8, by means of which the materials 20 from the various silos can be dropped into or on the lower conveyor 12 of the container weight and when the individual portions have been dispensed successively, the conveyor 12 is activated to dispense all the portions to a mixing device not shown, which can then deliver the respective mixing portion to a truck or tanker or to a relevant storage location for this particular mixing material. New raw materials may be supplied to the silos 4 from an elevator 14 which leads above the feed material through a downpour 16 to a conveyor 18 which transfers the material across the silos to a relevant downstream connection 20, at the top of these individual connections to the the silos are inserted shut-off damper 22, by means of which the downflow can be opened to the particular silo.

As far as described, this is a commonly known plant for preparing material mixtures, e.g. feed mixtures wherein various intended mixtures can be produced by selectively activating the outlets 8,10. Hereby, it is also customary from time to time to take samples of the materials for further analysis, namely upon receipt of the raw materials or when the materials are filled into the individual silos. Hereby the raw materials and the settlement for the same can be examined and checked with reference to the content of the materials, e.g. water and proteins, and in the event of changes, it will be possible to make necessary adjustments to the mixing recipes to maintain the essential ingredients of the mixing products. However, these assays are not overly useful if their associated results are not available until the contents of the individual silos have been used up.

Thus, it is far from sufficient to take samples from the deliveries of the raw materials or of the material filled into each silo, as frequent samples should be taken from the silo outlets, which has until now been considered practically impossible since the silo outlets above the container weight 6 is usually very difficult to access.

However, the invention seeks to allow frequent automatic sampling at these outlets 20 and for a rapid delivery of the samples to a fast-acting assay station associated with a computer equipment for quickly determining any necessary prescription corrections as well as performing these corrections, all in such a way that detected quality changes can be compensated already in the subsequent mixing portion or at least in the subsequent mixing portions and, if possible, already in the same portion as the one for which the change has been detected. It is sought to achieve a once-per-minute analysis and to keep the time from a sampling to a resulting change in prescription so short that this time will be of the same magnitude as the time required to prepare a single medium-sized blend portion, typically about . 6 minutes. Thus, within this range, multiple analyzes of the various raw materials used can be made.

This is mainly achieved by five different measures, albeit with associated auxiliary measures, namely, the sampling at the many silo outlets can be performed automatically using a simplified sampling equipment which may consist of only a single or a few, but movable samplers; 2) that the samples can be transferred to the assay center automatically through a pneumatic and fast-acting transport system; 3) that the samples may be delivered to the assay unit or to obtain such units in a manner acceptable from an industrial point of view; that is, with substantially increased capacity compared to a laboratory analysis and with the assurance that the successively spent samples will not leave deposits capable of contaminating the sample or subsequent sample portions 15 4) that the samples are continuously comminuted sufficiently to could be analyzed automatically according to The NIR principle or similar principles, and 5) that the analysis equipment is connected to an advanced computer system that can quickly perform the necessary adjustments to the material dosages in the event of any necessary prescription changes.

For carrying out these functions, the system of the invention comprises an automatic sampling device which is not to be described in detail in this specification, and an analyzing station 24 having an analyzing unit 26 which is preferably of the NIR type already known and therefore not to be known. is described in more detail here. The unit 26 has a detector head 28 to be brought into close light beam contact with the material samples, after which the unit 26 will quickly produce an analysis result. This result can be loaded into a computer equipment 30 which will serve to make the necessary adjustments to the blending recipes if changes in the grades of raw materials are revealed in the analyzes.

The illustrated system includes a number of sample receiving terminals 35, all of which are shown with the same signature and designated by 34. These terminals are connected to a system of pneumatic conveyor tubes 36 running together to a common suction tube 38 which is connected to the suction input of a cyclone 40 located near the analysis center 24. The cyclone has an upper air outlet 42 to a suction fan 44, and a cylindrical filter 46 is disposed around the associated central air outlet tube 46. The material separated into the cyclone leaves it through a flow damper 48 down to a feeder unit 50, at the bottom of which is provided a transverse conveyor screw 52 which can be selectively actuated to output the material to either side. When the material is discharged to the right, it is led to a conduit 54 connected to a suction conduit 58, 10 leading to another cyclone 60 constructed in the same manner as the cyclone 40 and connected to a separate suction fan 62. Its air outlet 64 is branched partly to the free passage through a valve 66 and partly to a return pressure line 68, the function of which is explained in more detail below. The material discharge from the cyclone 60 is passed through a shut-off valve 70 to a sample vessel 72 which is directly adjacent to the NIR analyzer 26 and has a lower flow line 74 leading through a shut-off valve 76 to a flow-through container 78 provided a sampler 80, 20 from which a collected sample may be extracted through a conduit 82 to a packing apparatus 84 for individual bag packaging of the samples. The bulk of the material will flow through the container 78 to a short conveyor screw 86, from which it is delivered to a quench container 88 connected at the bottom 25 to the pressure line 68 from the fan 62, and to a continuing pneumatic conveyor 90 branched through switch valves 92 a system of returning pneumatic conveying tubes 94 through which the successively supplied samples can be returned to the respective sampling areas.

30 As mentioned below, the sample materials conveyed through the pneumatic conveying system to the analyzing station 24 will already be disintegrated to such a degree that they can be safely transported, which is obtainable by relatively inexpensive and coarse disintegration devices at 35 each of the sample terminals. 34. However, for a fast and reliable NIR analysis, it is essential that the sample material be fed to the sample container 72 with a high degree of comminution, and to achieve this, a fine section apparatus 67 is provided in the assay station or in connection thereto. capable of receiving the material from the collecting container 50 when the auger 52 is actuated to discharge the material to the left; the finely cut material will exit the apparatus through a conduit 59, 5 connected to the suction pipe 58 through a shut-off valve. A corresponding valve is disposed in conduit portion 54.

In normal operation, the successive sample portions will be passed through the fine cutter 57 for delivery 25 to the cyclone 60 and to the sample container 72 in a pronounced fine cut 10 condition, and a passage through the conduit 52 passing around the fine cutter 57 will be effected only in such cases where is directly undesirable that the material passes the fine cutter.

Another and more important reason for passing the material around the cutter would be a finding that metal parts are present in the sample portion. The fine cutter, which must be designed in such a way that it can comminute the material extensively without retaining small residues of the material, will be a highly developed unit with a very fast rotating knife system which can process the usual test materials extremely effectively, but which so will also be quite vulnerable to metal parts that appear in the material. Larger metal parts and other large foreign bodies in the material can be retained by using lattice elements in the sample terminals 34, but a necessary detection of smaller metal parts can be carried out centrally, e.g. immediately at or before the introduction of the sample material into the collecting vessel 50. This can be easily accomplished by means of a metal detector 96 disposed in conjunction with the suction line 38.

The collecting container 50 should be able to receive a full sample portion before being passed to the fine cutter, namely to ensure that the whole portion can be passed around the fine cutter 57 whenever the metal detector 96 detects the presence of metal in any portion of the oncoming sample portion. A sample portion contaminated in this way could then be well disposed for collection as direct waste as it will be unfit to be analyzed already because it has not been finely cut, but it has been found more practical merely to allow such sample portions to be passed through the described system, possibly to return the sample portion to its sampling area or to the scrap silo, thereby merely ensuring that neither analyzer 26 nor the underlying sample 80 is activated upon emergence of a sample of this type.

It is shown in FIG. 1, it is shown that along an upwardly extending portion of the central suction tube 38, which may consist of a tube 98 of glass or other non-magnetic material, an elongated magnet 100 may be disposed which will act retardingly on 10 iron parts in the flow of material advanced. , so that at least a certain number of iron-contaminated samples will now be sufficiently purified to then be harmless to fine cutter 57 and not give rise to a distorted analytical result. The magnet may be disposed in such a way that it can be retracted from the pipe member 98, e.g. by means of a cylinder 102, whereby the trapped iron parts on the inside of the tube 98 may from time to time be released from the magnetic holding engagement and thus fall down through the tube to a lower shut-off valve 104.

The system may include a number of "loose" test terminals 34 ', e.g. as shown in the upper left of a laboratory or the like and, optionally, in a finished goods store 106, from which samples can be taken manually for pouring out in the sample terminal 341. These terminals have no fixed associated sampling area which the samples can be returned after the analysis. to, and instead, precisely these specimens can be passed to a waste collection site, e.g. a so-called scrap silo 107 in connection with the silo battery 2.

In FIG. 1, it is shown between the finished product storage 106 and the silo battery 2 that various processing equipment 108 with drain 110 can be found in the plant, in which there are samplers 112 which deliver the samples to a fixed connected sample terminal 34. Some of the devices may indicated to be suitable for receiving the sample material back from line 35, 90.94, while other of the devices are not suitable therefor.

At the bottom left is a finished goods store 114 with automatic sampling 116 which delivers the samples to associated sample terminals 34.

12 DK 171620 B1 In connection with the container weight 6,12 a special sampling equipment is arranged which is movable along the row of outlet 10 from the silos 4, so that it is able to take a sample from any of the outlets and bring the sample to 5. or several associated test terminals 34. This avoids the need to work with many separate samples, and it will be possible to return the analyzed samples to the silos from which the samples were taken, or to the scrap silo, through the supply units 120 shown.

10 For the safe transport of samples through the pneumatic system, it is important that sample portions of coarse material be comminuted, and it is therefore preferred that those of sample terminals 34 and 34 'which may be exposed to receive sample material of coarse nature are: designed as or with a disintegrating device for the material, and in practice it is preferred that all test terminals be constructed in this way. In connection with the invention, a special disintegrating unit has been developed which is further operative for controlled entrainment of the material in the lower part of the sample terminals, 20 from which the material is sucked into the transport system 36,38, which 'terminal disintegrator' is shown in FIG. 2nd

The FIG. 2, a housing with an upper receiving opening 121 above a pivotable closure plate 122 which can be pivoted to a dotted shown upright position 25, wherein it covers sample collection chamber 123 having an inclined bottom plate 124 leading down to a lower a cylindrical bottom portion 125. In this bottom portion 20 is placed a rotating cylinder 126 which is provided with projecting knife elements 126 'and with projecting axially extending plate ribs 127 formed with notches 128. Above the center of the rotor cylinder 126 is a wall portion 129, having a lower extension 130, to which is attached a series of upright flat iron pieces extending downwardly against the cylinder 126 in such a way that they can be passed by the notches 128 in the plate ribs 127 and also passed by the knife elements 126 ' in the spaces between the flat iron pieces 131.

Hereby, the rotor cylinder 126 will act both as a shredder and as a locking element which will lead the shredded material to the bottom part 125. This part has a lower ridge part 132 which at one end is connected to the suction line conduit 36 in the pneumatic conveying system while at the other end or side of the test terminal it is open towards the atmosphere. The tube 36 is provided with a solenoid valve 133 which is controlled from the overall control system.

When a sample is ready to be delivered to the terminal, actuating means shown to open the top plate 122 are not affected, and the entire sample is then passed into the collecting chamber 123, after which the plate 122 is closed. Then, when the control system calls for the sample to be delivered to the conveyor system, valve 133 is opened and rotor 126 is started, whereby the sample material is chopped into the collection trough and successively drawn into the tube 36 by the flow of air flowing through the trough. Material falling onto the closed top plate will step downwards and outwards through a slot 134 in a wall portion of the terminal.

The relatively large sample portions are thus fed here to the conveying system in a progressive manner, so that each of them can be continuously conveyed by means of the air already flowing through the collection channel. However, this requires some form of active entrainment into the airflow, since the pneumatic transport cannot be started if the air passage is completely blocked by transport material. In some sample containers, it may be unnecessary to use a chopper, and in these cases it may be desirable to completely avoid the motorized system. This will also apply, and especially in cases where it may be desirable to combine a sampler directly with a sample container, e.g. a sampler moving across a stream of material and having its container portion connected to the conveying system through a flexible hose. In many cases, it will be preferable to activate the sampler at a given time, namely when a material flow occurs for 35 sampling, and to delay the delivery of the sample to the transport system until it is appropriate to pass the sample to the analyzer, both here and at stationary sampling 14 DK 171620 B1 holders it may be desirable to start the suction from an already filled sample container.

In FIG. 3-5 are an example of a sampler designed for this purpose. It consists of a tubular body 200 formed with a longitudinal upper slot 202 and with an upright central wall 204 dividing the inner space into two halves 206 and 208. The space 208 is connected at one end to a hose 210 which leads for transporting the system through a solenoid valve not shown, while the two compartments at the opposite end are mutually connected by means of a hemispherical end cap 212. At the opposite end of the compartment 206, an air intake opening 214. There is disposed a partial cylindrical cover tube 206 which is rotatable between a closed and an open position relative to the top slot 202. On the partition wall 204 is provided a pair of opposing plate blades 218 extending outwardly down a portion of the width of the tube 200. On the pipe casing 216, a protruding triangular bead body 220 may be arranged opposite to its open slot.

When this sampler is placed in or moved through a 20 decreasing stream of material from which a sample is to be taken, the tube 200 may be filled with material as shown in FIG. 4. However, due to the wings 218, open air ducts 222 will be left underneath these wings in which the falling material cannot penetrate. These 25 ducts can form on both sides of the partition 204 an uninterrupted air passage between the suction hose 210 and the air inlet opening a 214, and when suction is applied to the hose 210 it is thus possible to generate an air flow through the sample material and thereby be started and soon thereafter exhausted. -30 of the material. However, this may, of course, require the slot 202 to be closed by the cap tube 216.

Correspondingly, air ducts 222 could alternatively be provided underneath wings or other substantially horizontal shielding means extending inwardly from an outer side portion of the container tube 200, as well as being stationary.

The analyzing unit 26 may be arranged in such a way that it can effect the necessary adjustments within certain limits for divergent material properties, while for atypical deviations it may be desirable to carry out a more detailed and traditional chemical analysis which will also involve a check on whether it can be the unit of analysis that produces the wrong results. The automatic control can hereby be arranged to activate the sampler 80 in the flow chamber 78, whereby a small portion of the relevant sample material can be isolated and fed to the packaging unit 84 for collection in a bag which can then be brought to a specialized analysis laboratory. The packaging or bag filler unit 84 may be provided with computer controlled means for identifying the samples.

In FIG. 6 and 7 are shown a fin divider 57 specially developed in connection with the invention. This is a cutter mill with a fast rotating knife rotor 135 having fixed 15 radial knives 136 rotating in a cylindrical housing 137 having an upper side inlet 138 and a tangential bottom outlet 139. The rotor is driven by a motor not shown. and comprises a core 140 with an extended upper portion 142 and with plate flanges 144 spaced apart in axial direction. Rectangular steel rods 146 are mounted on four rods 20 which extend axially over the entire height of the rotor through corresponding rectangular holes in portions 142 and 144, and in the spaces between these rods are arranged a plurality of spaced blades 132 on these rods. each having a rectangular hole for receiving the rod 146 in such a way that these blades are mounted with a very high degree of rigidity on the rotor, which is unusual for an apparatus of this type. The object is to provide an apparatus which is highly efficient in terms of capacity and cutting finesse, and for this purpose the rotor 30 should be operated very quickly, e.g. at 3000-6000 rpm. just as the knife ends should sweep along the inside of the housing 134 for a very short distance therefrom, in practice with a distance of 1-1.5 mm. These conditions together impose very high quality requirements for achieving high reliability, and it is on this basis that the blades are fixedly mounted, as is the rotor in bearings at both ends.

The housing 137 may have an open side portion for inspection of the blades, and said bars 146 may be arranged to lift up through a hole 148 in the top cover 15 of the housing when the blades are positioned next to the opened side portion so that the blades can be replaced without the rotor having to be removed from the housing.

5 It is essential to be able to control the flow of material through the apparatus. This could be done by means of compressed air nozzles arranged for blowing the material, but in FIG.

6 illustrates a preferred embodiment in which the cut material is extracted from the lower outlet 138 by means of a suction fan 150 and excreted by means of a cyclone 152, from which it is delivered to the analysis station. The suction air is introduced into the housing 135 through the upper inlet 136, forming a hole 154, in which, as shown by an arrow, an air flow is generally produced, which is generally downwardly along the inside of the housing, whereby the material is directed downward as it is processed. through the blades. Thus, by applying a greater or less suction to the outlet, it is possible to control the flow time of the individual sample portions in order to minimize the time for producing a sufficiently fine cut material.

It is desirable to work with extremely sharp blades 132, which could necessitate costly machining of the blades. However, it has been found that using uniform knife bodies of insert hardened flat iron does not need to sharpen the blades, because after a relatively short run-in period it will have occurred that the edge of the middle layer of the knife bodies will be noticeably worn, while the outer surface layers are practically non-abrasive, so that very sharp edge portions are automatically formed along the upper and lower sides of the protruding knife bodies.

As mentioned, air nozzles may be used inside the housing 134, preferably for performing a rapid blowout of any treated material portion and for subsequent air flushing of the interior of the housing. Such nozzles are shown at 35 156 in FIG. 6, where the nozzles are shown integrally in the housing, but since the nozzles can thereby collect material at their upper sides, they are preferably arranged in such a way that, as shown at the lower nozzle, they can be pulled outwards e.g. by means of a cylinder 17 158 so that they can be kept extended during the operating periods.

It has already been mentioned that in the invention there may be another special problem, namely the cleaning of the area next to the detector head 28, and one of the mentioned solutions of this problem is illustrated in FIG. 8, wherein said side hole in the sample container 72 is designated 160. The analyzer 26 is shown to be pulled away from this hole, but normally the units concerned may remain tightly assembled. Over the outside of the hole 160 is placed a roll film 161 consisting of a suitable transparent material such as Teflon which has no significant influence on the measurement results; this film is automatically advanced incrementally past the hole 160, from a unwinding coil 162 to a winding coil 164. Inside the container 72 is a plunger 166 which can be displaced in the transverse direction by a pressure cylinder 168 so that the piston can push the loose material in the container toward the hole 160 to allow for proper analysis. The pressure will be absorbed by the tire disc on the detector head 28, but with the film 201 as a separating surface which will physically isolate the material from the tire disc.

After performing the analysis and withdrawing the plunger 166 and removing the material from the container 72, the film 161 is advanced a step to remove the hollow 25 region and to advance a new and totally clean film piece so that the next sample can be analyzed without some trace of the previous material sample appears. The film strip 161 may be used. is replaced by a rotating disc which can add new and possibly successively cleaned film areas to the hole 160, the hollow-covering portions of such a disc being passed through an outer unit containing means for automatically cleaning the disc material.

The film 161 and the coils 162 and 164 may conveniently be placed in a cassette for easy replacement when the film is used up.

Claims (11)

18 DK 171620 B1 1. A method for handling particulate sample materials in silos, mixing stations, process plants or generally in plants for receiving, processing or delivering materials, where material samples are regularly taken from an internal analysis station (24,26), characterized in that the samples are taken successively at different locations and transferred to a pneumatic conveying system (36,38), wherein the samples in unpackaged condition are successively passed to the analysis station through transport tube lengths, some of which are common to the sample transfer from several sampling points, taking the samples. and transported in sufficient volume that residues of pre-transported samples in the transport system upon admixture in the following sample portion will only contaminate it to an acceptable degree. Method according to claim 1, characterized in that the sample portions are collected successively in a corresponding large sample container (72) in the analysis station and that the analysis is carried out according to a surface irradiation principle such as NIR using a detector head (28) which is made to cooperate with a surface portion of the sample material in the container (72), preferably at a suitably prepared sidewall area 25 thereof. Method according to claim 1 or 2, characterized in that, after being analyzed, sample portions are transported back from the sample container (72) through a selectively controllable pneumatic conveying system (90) to the respective regions from which the samples originate. Method according to claim 2, characterized in that the samples, after being analyzed, are discharged from the sample container (72) through a sampling chamber (78), in which a sampler (80) is activated, after an atypical analysis, to take a small control sample. For further analysis, the control sample is preferably passed to a packaging unit (84) for packaging, identification marking and delivery of the control sample thus packaged. Method according to claim 1, wherein the sample material is easily comminuted prior to analysis, characterized in that the sample material is passed from the sampler to the transport system at each relevant sampling point through an associated disintegrator (126) which can sufficiently disintegrate the material to do so. transportable, and that the material is fed to the analysis station from the transport system through a atomizer (57) which further decomposes the material for preparation for analysis. A mixing, storage or process plant for carrying out the method of claim 1, comprising a plurality of material sources (2), e.g. silos having means (8,10) for controlled discharge of the materials therefrom, and means (112,118) for sampling from the outlet streams and means (26) for analyzing these samples, characterized in that the sampling means are adapted for successively delivering sample portions in unpackaged condition to respective entry points (34) in a branched pneumatic conveying system (36,38), which culminates in a central analysis station (24), wherein 25 are provided (26) for automatically analyzing the successively received samples since the sampling means (112,118) take sample portions of sufficient size, preferably more than 1 liter, that the sample portions, when mixed with the residual amounts of sample material present in the transport system from pre-transported samples, will only be contaminated to an acceptable degree for the analysis results. . System according to claim 6, characterized in that the analysis station (24) comprises a sample container (72) for successively receiving at least a substantial part of each of the sample portions carried forward and an analysis equipment (26, 28) of a such a type which can analyze the material by irradiating a surface area thereof, which equipment DK 171620 B1 20 cooperates with a defined surface area of the collected sample portion, preferably through a window in a side wall of the sample container (72). Installation according to claim 6, characterized in that the outlet end of the sample container (72) is connected to a return transport system (90) through which the samples are returned to their respective starting areas. Installation according to claim 6, characterized in that in the connection between the sampling means (112, 118) and the respective sampling points (34) of the transport system, decomposing units (126) are arranged which can disintegrate the materials sufficiently to make them safely transportable in the transport system. pneumatic conveying system. System according to claim 6, characterized in that in the pneumatic conveying system (38) and adjacent to the analysis station (24) a central comminuting unit (57) is arranged for further comminution of the material in otherwise known manner in the successively received samples prior to their analysis. System according to claim 6, characterized in that, in connection with the pneumatic conveying system, sample entry points are provided in the form of receiving terminals (34,34 '), some of which (34) are operatively coupled to respective sampling means (112,118), while others ( 34 ') are freely available. 30 35